PMID- 19935926
OWN - NLM
STAT- MEDLINE
DCOM- 20100305
LR  - 20220321
IS  - 1480-3321 (Electronic)
IS  - 0831-2796 (Linking)
VI  - 52
IP  - 9
DP  - 2009 Sep
TI  - Extensive NOR site polymorphism in geographically isolated populations of Golden 
      mahseer, Tor putitora.
PG  - 783-9
LID - 10.1139/g09-052 [doi]
AB  - Analyses of nucleolar organizer region (NOR) site polymorphism using silver 
      staining were carried out in 72 individuals of 5 geographically isolated 
      populations of Tor putitora from India. All Ag-NORs analyzed were constituted by 
      rDNA that was confirmed by the presence of positive fluorescence in situ 
      hybridization (FISH) signals. Analyses of the extra NORs among the populations 
      confirmed the hypothesis that multi-chromosomal NOR site polymorphism is not an 
      exception but a rule. We found a negative correlation between the mean number of 
      extra NORs and geographical distance from the Alaknanda River population, and a 
      significant positive correlation between the genetic distances obtained by NOR 
      data and geographical distances among the isolated populations. These findings 
      suggest a single geographical origin of this NOR polymorphism, from which it 
      might have radiated to neighboring populations before their isolation. The 
      distribution of NOR site variation was compared with the sequence variation of 
      the ITS1 region of major rDNA (45S) and the two were found to be positively 
      related. Different mechanisms such as transposable elements adjacent to ribosomal 
      genes, repetitive elements which could serve as a point for chromosome exchange, 
      amplification of minor rDNA loci, and reinsertion of extrachromosomal rDNA 
      amplified during oogenesis have been proposed to explain the apparent NOR site 
      polymorphism. The high dispersion of NOR site variants within and among the 
      populations suggests that whatever transposition phenomenon is responsible for 
      repetitive DNA or NOR jumping, it could still be active in T. putitora.
FAU - Singh, Mamta
AU  - Singh M
AD  - National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, 
      Lucknow 226 002, U.P., India.
FAU - Kumar, Ravindra
AU  - Kumar R
FAU - Nagpure, N S
AU  - Nagpure NS
FAU - Kushwaha, B
AU  - Kushwaha B
FAU - Mani, Indra
AU  - Mani I
FAU - Lakra, W S
AU  - Lakra WS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Canada
TA  - Genome
JT  - Genome
JID - 8704544
RN  - 0 (DNA, Ribosomal)
RN  - 0 (DNA, Ribosomal Spacer)
SB  - IM
MH  - Animals
MH  - Cypriniformes/classification/*genetics
MH  - DNA, Ribosomal/chemistry/genetics
MH  - DNA, Ribosomal Spacer/chemistry/genetics
MH  - Genetic Variation
MH  - Genotype
MH  - Geography
MH  - In Situ Hybridization, Fluorescence
MH  - India
MH  - Karyotyping
MH  - Nucleolus Organizer Region/*genetics
MH  - *Polymorphism, Genetic
MH  - Sequence Analysis, DNA
MH  - Species Specificity
EDAT- 2009/11/26 06:00
MHDA- 2010/03/06 06:00
CRDT- 2009/11/26 06:00
PHST- 2009/11/26 06:00 [entrez]
PHST- 2009/11/26 06:00 [pubmed]
PHST- 2010/03/06 06:00 [medline]
AID - g09-052 [pii]
AID - 10.1139/g09-052 [doi]
PST - ppublish
SO  - Genome. 2009 Sep;52(9):783-9. doi: 10.1139/g09-052.